/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans SC', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 通用样式 */
.section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-header h2 {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 15px;
    color: #2c3e50;
    position: relative;
    display: inline-block;
}

.section-header h2:after {
    content: '';
    position: absolute;
    width: 60px;
    height: 3px;
    background-color: #3498db;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
}

.section-header p {
    font-size: 18px;
    color: #7f8c8d;
    max-width: 600px;
    margin: 0 auto;
}

.bg-light {
    background-color: #f8f9fa;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 12px 30px;
    font-size: 16px;
    font-weight: 500;
    text-align: center;
    text-decoration: none;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background-color: #3498db;
    color: white;
    border: 1px solid #3498db;
}

.btn-primary:hover {
    background-color: #2980b9;
    border-color: #2980b9;
}

.btn-secondary {
    background-color: transparent;
    color: #3498db;
    border: 1px solid #3498db;
}

.btn-secondary:hover {
    background-color: #3498db;
    color: white;
}

/* 导航栏样式 */
header {
    background-color: #fff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.logo a {
    font-size: 24px;
    font-weight: 700;
    color: #2c3e50;
    text-decoration: none;
}

.main-nav ul {
    display: flex;
    list-style: none;
}

.main-nav ul li {
    margin-left: 30px;
}

.main-nav ul li a {
    color: #333;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.main-nav ul li a:after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    background-color: #3498db;
    bottom: -5px;
    left: 0;
    transition: width 0.3s ease;
}

.main-nav ul li a:hover,
.main-nav ul li a.active {
    color: #3498db;
}

.main-nav ul li a:hover:after,
.main-nav ul li a.active:after {
    width: 100%;
}

.mobile-menu-toggle {
    display: none;
    font-size: 24px;
    cursor: pointer;
}

/* 主页横幅样式 */
.hero {
    background: linear-gradient(rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 0.6)), url('https://picsum.photos/seed/plastic-materials/1920/1080.jpg') no-repeat center center/cover;
    height: 100vh;
    display: flex;
    align-items: center;
    text-align: center;
    color: #fff;
    margin-top: 70px;
}

.hero-content h1 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 20px;
    animation: fadeInUp 1s ease;
}

.hero-content p {
    font-size: 20px;
    max-width: 700px;
    margin: 0 auto 30px;
    animation: fadeInUp 1s ease 0.2s;
    animation-fill-mode: both;
}

.hero-content .btn {
    animation: fadeInUp 1s ease 0.4s;
    animation-fill-mode: both;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 关于我们部分样式 */
.about-content {
    display: flex;
    align-items: center;
    gap: 50px;
}

.about-text {
    flex: 1;
}

.about-text p {
    margin-bottom: 20px;
    font-size: 16px;
    line-height: 1.8;
}

.about-stats {
    display: flex;
    margin-top: 30px;
    gap: 30px;
}

.stat {
    text-align: center;
    flex: 1;
}

.stat-number {
    display: block;
    font-size: 36px;
    font-weight: 700;
    color: #3498db;
    margin-bottom: 5px;
}

.stat-label {
    font-size: 14px;
    color: #7f8c8d;
}

.about-image {
    flex: 1;
}

.about-image img {
    width: 100%;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

/* 产品中心部分样式 */
.category-tabs {
    display: flex;
    justify-content: center;
    margin-bottom: 40px;
}

.tab-btn {
    padding: 10px 25px;
    margin: 0 5px;
    background-color: #fff;
    border: 1px solid #ddd;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
}

.tab-btn.active,
.tab-btn:hover {
    background-color: #3498db;
    color: white;
    border-color: #3498db;
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 30px;
}

.product-card {
    background-color: #fff;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.product-image {
    height: 200px;
    overflow: hidden;
}

.product-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.product-card:hover .product-image img {
    transform: scale(1.05);
}

.product-info {
    padding: 20px;
}

.product-info h3 {
    font-size: 18px;
    margin-bottom: 10px;
    color: #2c3e50;
}

.product-info p {
    font-size: 14px;
    color: #7f8c8d;
    margin-bottom: 15px;
}

.product-info .btn {
    font-size: 14px;
    padding: 8px 20px;
}

/* 应用领域部分样式 */
.applications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 30px;
}

.application-card {
    background-color: #fff;
    border-radius: 8px;
    padding: 30px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.application-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.application-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto 20px;
    background-color: #ebf5fb;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.application-icon i {
    font-size: 30px;
    color: #3498db;
}

.application-card h3 {
    font-size: 20px;
    margin-bottom: 15px;
    color: #2c3e50;
}

.application-card p {
    font-size: 15px;
    color: #7f8c8d;
}

/* 质量保证部分样式 */
.quality-content {
    display: flex;
    align-items: center;
    gap: 50px;
}

.quality-text {
    flex: 1;
}

.quality-item {
    margin-bottom: 25px;
}

.quality-item h3 {
    font-size: 18px;
    margin-bottom: 10px;
    color: #2c3e50;
    display: flex;
    align-items: center;
}

.quality-item h3 i {
    margin-right: 10px;
    color: #3498db;
}

.quality-item p {
    font-size: 15px;
    color: #7f8c8d;
    padding-left: 30px;
}

.quality-image {
    flex: 1;
}

.quality-image img {
    width: 100%;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

/* 联系我们部分样式 */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
}

.contact-item {
    margin-bottom: 25px;
}

.contact-item h3 {
    font-size: 18px;
    margin-bottom: 10px;
    color: #2c3e50;
    display: flex;
    align-items: center;
}

.contact-item h3 i {
    margin-right: 10px;
    color: #3498db;
}

.contact-item p {
    font-size: 16px;
    color: #7f8c8d;
    padding-left: 30px;
}

.contact-form {
    background-color: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
}

.form-group {
    margin-bottom: 20px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: #3498db;
    outline: none;
}

/* 页脚样式 */
footer {
    background-color: #2c3e50;
    color: #ecf0f1;
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 30px;
    margin-bottom: 40px;
}

.footer-logo h3 {
    font-size: 24px;
    margin-bottom: 15px;
    color: #fff;
}

.footer-logo p {
    font-size: 16px;
    color: #bdc3c7;
}

.footer-links h4,
.footer-contact h4 {
    font-size: 18px;
    margin-bottom: 20px;
    color: #fff;
    position: relative;
    padding-bottom: 10px;
}

.footer-links h4:after,
.footer-contact h4:after {
    content: '';
    position: absolute;
    width: 40px;
    height: 2px;
    background-color: #3498db;
    bottom: 0;
    left: 0;
}

.footer-links ul {
    list-style: none;
}

.footer-links ul li {
    margin-bottom: 10px;
}

.footer-links ul li a {
    color: #bdc3c7;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-links ul li a:hover {
    color: #3498db;
}

.footer-contact p {
    margin-bottom: 10px;
    color: #bdc3c7;
}

.footer-contact p i {
    margin-right: 10px;
    color: #3498db;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #34495e;
    font-size: 14px;
    color: #95a5a6;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .about-content,
    .quality-content {
        flex-direction: column;
        gap: 30px;
    }

    .about-image,
    .quality-image {
        order: -1;
    }

    .contact-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .main-nav {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background-color: #fff;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease;
        z-index: 999;
    }
    
    .main-nav.active {
        max-height: 400px;
    }
    
    .main-nav ul {
        flex-direction: column;
        padding: 20px;
    }
    
    .main-nav ul li {
        margin: 0;
        padding: 10px 0;
        border-bottom: 1px solid #eee;
    }
    
    .main-nav ul li:last-child {
        border-bottom: none;
    }
    
    .main-nav ul li a {
        display: block;
        padding: 10px 0;
    }
    
    .mobile-menu-toggle {
        display: block;
    }

    .hero {
        height: 80vh;
    }

    .hero-content h1 {
        font-size: 36px;
    }

    .section {
        padding: 60px 0;
    }

    .section-header h2 {
        font-size: 28px;
    }

    .about-stats {
        flex-wrap: wrap;
    }

    .stat {
        flex-basis: 50%;
        margin-bottom: 20px;
    }

    .category-tabs {
        flex-wrap: wrap;
    }

    .tab-btn {
        margin-bottom: 10px;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-links h4:after,
    .footer-contact h4:after {
        left: 50%;
        transform: translateX(-50%);
    }
}

@media (max-width: 576px) {
    .stat {
        flex-basis: 100%;
    }

    .applications-grid {
        grid-template-columns: 1fr;
    }
}